A chemical change can release energy where does the energy come from

The chemical energy is a part of all chemical reactions. Energy is needed to break down chemical bonds in starting substances. As new bonds form in final substances. But chemical energy of the original substances will be the same as chemical energy of the final substances. So you don't lose nor gain any energy in the overall reaction.

The energy of a chemical reaction comes from the breaking of the old bonds and forming new bonds with the atoms.